X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fmovepick.cpp;h=208007cca24e84d7a54ac0ef1c4844b23e844161;hp=8872e39f3691a8740a8ba1244f8fc3c4664951c5;hb=351ef5c85b6d4b9c71e9da367f0be5ab6e6f8117;hpb=c9d7e99de682516c560009b550c41da9ae2008b8 diff --git a/src/movepick.cpp b/src/movepick.cpp index 8872e39f..208007cc 100644 --- a/src/movepick.cpp +++ b/src/movepick.cpp @@ -28,82 +28,75 @@ namespace { enum MovegenPhase { - PH_TT_MOVES, // Transposition table move and mate killer - PH_GOOD_CAPTURES, // Queen promotions and captures with SEE values >= 0 + PH_TT_MOVE, // Transposition table move + PH_GOOD_CAPTURES, // Queen promotions and captures with SEE values >= captureThreshold (captureThreshold <= 0) + PH_GOOD_PROBCUT, // Queen promotions and captures with SEE values > captureThreshold (captureThreshold >= 0) PH_KILLERS, // Killer moves from the current ply - PH_NONCAPTURES, // Non-captures and underpromotions - PH_BAD_CAPTURES, // Queen promotions and captures with SEE values < 0 + PH_NONCAPTURES_1, // Non-captures and underpromotions with positive score + PH_NONCAPTURES_2, // Non-captures and underpromotions with non-positive score + PH_BAD_CAPTURES, // Queen promotions and captures with SEE values < captureThreshold (captureThreshold <= 0) PH_EVASIONS, // Check evasions PH_QCAPTURES, // Captures in quiescence search + PH_QRECAPTURES, // Recaptures in quiescence search PH_QCHECKS, // Non-capture checks in quiescence search PH_STOP }; CACHE_LINE_ALIGNMENT - const uint8_t MainSearchTable[] = { PH_TT_MOVES, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES, PH_BAD_CAPTURES, PH_STOP }; - const uint8_t EvasionTable[] = { PH_TT_MOVES, PH_EVASIONS, PH_STOP }; - const uint8_t QsearchWithChecksTable[] = { PH_TT_MOVES, PH_QCAPTURES, PH_QCHECKS, PH_STOP }; - const uint8_t QsearchWithoutChecksTable[] = { PH_TT_MOVES, PH_QCAPTURES, PH_STOP }; + const uint8_t MainSearchTable[] = { PH_TT_MOVE, PH_GOOD_CAPTURES, PH_KILLERS, PH_NONCAPTURES_1, PH_NONCAPTURES_2, PH_BAD_CAPTURES, PH_STOP }; + const uint8_t EvasionTable[] = { PH_TT_MOVE, PH_EVASIONS, PH_STOP }; + const uint8_t QsearchWithChecksTable[] = { PH_TT_MOVE, PH_QCAPTURES, PH_QCHECKS, PH_STOP }; + const uint8_t QsearchWithoutChecksTable[] = { PH_TT_MOVE, PH_QCAPTURES, PH_STOP }; + const uint8_t QsearchRecapturesTable[] = { PH_TT_MOVE, PH_QRECAPTURES, PH_STOP }; + const uint8_t ProbCutTable[] = { PH_TT_MOVE, PH_GOOD_PROBCUT, PH_STOP }; } - -/// Constructor for the MovePicker class. Apart from the position for which -/// it is asked to pick legal moves, MovePicker also wants some information +/// Constructors for the MovePicker class. As arguments we pass information /// to help it to return the presumably good moves first, to decide which /// moves to return (in the quiescence search, for instance, we only want to /// search captures, promotions and some checks) and about how important good /// move ordering is at the current node. MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, - SearchStack* ss, Value beta) : pos(p), H(h) { - int searchTT = ttm; - ttMoves[0].move = ttm; - badCaptureThreshold = 0; + SearchStack* ss, Value beta) : pos(p), H(h), depth(d) { + captureThreshold = 0; badCaptures = moves + MAX_MOVES; assert(d > DEPTH_ZERO); - pinned = p.pinned_pieces(pos.side_to_move()); - - if (p.is_check()) + if (p.in_check()) { - ttMoves[1].move = killers[0].move = killers[1].move = MOVE_NONE; + killers[0].move = killers[1].move = MOVE_NONE; phasePtr = EvasionTable; } else { - ttMoves[1].move = (ss->mateKiller == ttm) ? MOVE_NONE : ss->mateKiller; - searchTT |= ttMoves[1].move; killers[0].move = ss->killers[0]; killers[1].move = ss->killers[1]; // Consider sligtly negative captures as good if at low // depth and far from beta. if (ss && ss->eval < beta - PawnValueMidgame && d < 3 * ONE_PLY) - badCaptureThreshold = -PawnValueMidgame; + captureThreshold = -PawnValueMidgame; phasePtr = MainSearchTable; } - phasePtr += int(!searchTT) - 1; + ttMove = (ttm && pos.move_is_pl(ttm) ? ttm : MOVE_NONE); + phasePtr += int(ttMove == MOVE_NONE) - 1; go_next_phase(); } -MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h) +MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h, Square recaptureSq) : pos(p), H(h) { - int searchTT = ttm; - ttMoves[0].move = ttm; - ttMoves[1].move = MOVE_NONE; assert(d <= DEPTH_ZERO); - pinned = p.pinned_pieces(pos.side_to_move()); - - if (p.is_check()) + if (p.in_check()) phasePtr = EvasionTable; else if (d >= DEPTH_QS_CHECKS) phasePtr = QsearchWithChecksTable; - else + else if (d >= DEPTH_QS_RECAPTURES) { phasePtr = QsearchWithoutChecksTable; @@ -111,10 +104,35 @@ MovePicker::MovePicker(const Position& p, Move ttm, Depth d, const History& h) // qsearch tree explosion due to a possible perpetual check or // similar rare cases when TT table is full. if (ttm != MOVE_NONE && !pos.move_is_capture_or_promotion(ttm)) - searchTT = ttMoves[0].move = MOVE_NONE; + ttm = MOVE_NONE; } + else + { + phasePtr = QsearchRecapturesTable; + recaptureSquare = recaptureSq; + ttm = MOVE_NONE; + } + + ttMove = (ttm && pos.move_is_pl(ttm) ? ttm : MOVE_NONE); + phasePtr += int(ttMove == MOVE_NONE) - 1; + go_next_phase(); +} + +MovePicker::MovePicker(const Position& p, Move ttm, const History& h, PieceType parentCapture) + : pos(p), H(h) { + + assert (!pos.in_check()); + + // In ProbCut we consider only captures better than parent's move + captureThreshold = piece_value_midgame(Piece(parentCapture)); + phasePtr = ProbCutTable; + + if ( ttm != MOVE_NONE + && (!pos.move_is_capture(ttm) || pos.see(ttm) <= captureThreshold)) + ttm = MOVE_NONE; - phasePtr += int(!searchTT) - 1; + ttMove = (ttm && pos.move_is_pl(ttm) ? ttm : MOVE_NONE); + phasePtr += int(ttMove == MOVE_NONE) - 1; go_next_phase(); } @@ -128,12 +146,12 @@ void MovePicker::go_next_phase() { phase = *(++phasePtr); switch (phase) { - case PH_TT_MOVES: - curMove = ttMoves; - lastMove = curMove + 2; + case PH_TT_MOVE: + lastMove = curMove + 1; return; case PH_GOOD_CAPTURES: + case PH_GOOD_PROBCUT: lastMove = generate(pos, moves); score_captures(); return; @@ -143,10 +161,17 @@ void MovePicker::go_next_phase() { lastMove = curMove + 2; return; - case PH_NONCAPTURES: - lastMove = generate(pos, moves); + case PH_NONCAPTURES_1: + lastNonCapture = lastMove = generate(pos, moves); score_noncaptures(); - sort_moves(moves, lastMove, &lastGoodNonCapture); + sort_moves(moves, lastNonCapture, &lastMove); + return; + + case PH_NONCAPTURES_2: + curMove = lastMove; + lastMove = lastNonCapture; + if (depth >= 3 * ONE_PLY) + insertion_sort(curMove, lastMove); return; case PH_BAD_CAPTURES: @@ -157,7 +182,7 @@ void MovePicker::go_next_phase() { return; case PH_EVASIONS: - assert(pos.is_check()); + assert(pos.in_check()); lastMove = generate(pos, moves); score_evasions(); return; @@ -167,6 +192,10 @@ void MovePicker::go_next_phase() { score_captures(); return; + case PH_QRECAPTURES: + lastMove = generate(pos, moves); + return; + case PH_QCHECKS: lastMove = generate(pos, moves); return; @@ -207,11 +236,11 @@ void MovePicker::score_captures() { for (MoveStack* cur = moves; cur != lastMove; cur++) { m = cur->move; + cur->score = piece_value_midgame(pos.piece_on(move_to(m))) + - pos.type_of_piece_on(move_from(m)); + if (move_is_promotion(m)) - cur->score = QueenValueMidgame; - else - cur->score = pos.midgame_value_of_piece_on(move_to(m)) - - pos.type_of_piece_on(move_from(m)); + cur->score += QueenValueMidgame; } } @@ -246,7 +275,7 @@ void MovePicker::score_evasions() { if ((seeScore = pos.see_sign(m)) < 0) cur->score = seeScore - History::MaxValue; // Be sure we are at the bottom else if (pos.move_is_capture(m)) - cur->score = pos.midgame_value_of_piece_on(move_to(m)) + cur->score = piece_value_midgame(pos.piece_on(move_to(m))) - pos.type_of_piece_on(move_from(m)) + History::MaxValue; else cur->score = H.value(pos.piece_on(move_from(m)), move_to(m)); @@ -254,7 +283,7 @@ void MovePicker::score_evasions() { } /// MovePicker::get_next_move() is the most important method of the MovePicker -/// class. It returns a new legal move every time it is called, until there +/// class. It returns a new pseudo legal move every time it is called, until there /// are no more moves left. It picks the move with the biggest score from a list /// of generated moves taking care not to return the tt move if has already been /// searched previously. Note that this function is not thread safe so should be @@ -271,52 +300,51 @@ Move MovePicker::get_next_move() { switch (phase) { - case PH_TT_MOVES: - move = (curMove++)->move; - if ( move != MOVE_NONE - && pos.move_is_legal(move, pinned)) - return move; + case PH_TT_MOVE: + curMove++; + return ttMove; break; case PH_GOOD_CAPTURES: move = pick_best(curMove++, lastMove).move; - if ( move != ttMoves[0].move - && move != ttMoves[1].move - && pos.pl_move_is_legal(move, pinned)) + if (move != ttMove) { + assert(captureThreshold <= 0); // Otherwise we must use see instead of see_sign + // Check for a non negative SEE now int seeValue = pos.see_sign(move); - if (seeValue >= badCaptureThreshold) + if (seeValue >= captureThreshold) return move; // Losing capture, move it to the tail of the array, note - // that move has now been already checked for legality. + // that move has now been already checked for pseudo legality. (--badCaptures)->move = move; badCaptures->score = seeValue; } break; + case PH_GOOD_PROBCUT: + move = pick_best(curMove++, lastMove).move; + if ( move != ttMove + && pos.see(move) > captureThreshold) + return move; + break; + case PH_KILLERS: move = (curMove++)->move; if ( move != MOVE_NONE - && pos.move_is_legal(move, pinned) - && move != ttMoves[0].move - && move != ttMoves[1].move + && pos.move_is_pl(move) + && move != ttMove && !pos.move_is_capture(move)) return move; break; - case PH_NONCAPTURES: - // Sort negative scored moves only when we get there - if (curMove == lastGoodNonCapture) - insertion_sort(lastGoodNonCapture, lastMove); - + case PH_NONCAPTURES_1: + case PH_NONCAPTURES_2: move = (curMove++)->move; - if ( move != ttMoves[0].move - && move != ttMoves[1].move + if ( move != ttMove && move != killers[0].move - && move != killers[1].move - && pos.pl_move_is_legal(move, pinned)) + && move != killers[1].move) return move; break; @@ -327,15 +355,19 @@ Move MovePicker::get_next_move() { case PH_EVASIONS: case PH_QCAPTURES: move = pick_best(curMove++, lastMove).move; - if ( move != ttMoves[0].move - && pos.pl_move_is_legal(move, pinned)) + if (move != ttMove) + return move; + break; + + case PH_QRECAPTURES: + move = (curMove++)->move; + if (move_to(move) == recaptureSquare) return move; break; case PH_QCHECKS: move = (curMove++)->move; - if ( move != ttMoves[0].move - && pos.pl_move_is_legal(move, pinned)) + if (move != ttMove) return move; break;